@mixin a-default {
  text-decoration: none;
  color: #ffffff;
}

@mixin loading {
  width: 80px;
  height: 40px;
  margin: 0 auto;
  margin-top: 100px;
  span {
    display: inline-block;
    width: 8px;
    height: 100%;
    border-radius: 4px;
    background: lightgreen;
    animation: load 1s ease infinite;
  }
  @keyframes load {
    0%,
    100% {
      height: 40px;
      background: lightgreen;
    }
    50% {
      height: 70px;
      margin: -15px 0;
      background: lightblue;
    }
  }
  span:nth-child(2) {
    animation-delay: 0.2s;
  }
  span:nth-child(3) {
    animation-delay: 0.4s;
  }
  span:nth-child(4) {
    animation-delay: 0.6s;
  }
  span:nth-child(5) {
    animation-delay: 0.8s;
  }
}
